Method of and apparatus for controlling humidification of air



O.l T. MERWIN METHOD OF' AND APPARATUS FOR CONTROLLING HUMIDIFICATION-OF AIR Filed Dec. 20, 1947 July 31, 1951 JNVENTOR. Uwe@ T. M erw/21 Patented July 31, 1951 UNITED STATES PATENT oFF-FICE lMETHODOF AND APPARATUS FOR CON- TRQLLINGHUMIDIFIGATIQN OF AIR Owen T. Merwin, Brooklyn, N. Y., assignor lto Buensod-Stacey, Inc., New'York,`N. Y., a corporation of Delaware ApplicationDecember 20, 1947, Serial No. .793,033

.a ,hygrostat which would sense the humidity :change and, 4acting through a pneumatically vactuated relaygwould operate to turn lthe atomizer headson and on?.

The. action of an atomzeris such that it atom- Aires the .water asnely as practicable so that the Sensible heat in the air produced bymachinery will vaporize the water. However, it has .been vvalways-a problem tozget a uniformity of humidity conditions `whenjree Ywater is added to the air. In actual practiceit requires a very sensitive and quickly operating hygrostat, principally so that v thelargeimass of unvaporized watercoming from the -atomizers `does not concentrate in definite .spots and therefore yif the time elementduring which theatomizersoperate is so long, say over to 40 seconds, the free water will not be vaporized yand Willget down where the vmachinery is, which, lot course, would lower the dry bulb quickly, therebyraising the relative-humidity above the desired .humidity limits.

The principal object of the present invention is to provide a control for humidity conditions vWithin a conditioned space within very narrow limits, say 2% of a prescribed relative humidity. ThisI accomplish vby using a hygrostat in ,conjunction with Yan air pressure systemcomprising pneumatic relays, check valvesand restricter valves, Iwhich function to control and limit the time .intervals that the atomizers can perform their duty and ,also the time that they Iwould b e oi duty and automatically operable means kfor interrupting the cycling when the humidity in the conditioned space is at the higher of the prescribed limits. By such method of cycling, overfhumidicationdue to the dropping ofglobulesofiree water is prevented. The invention will be better understood from the detailed description .whichfollows when considered in .connection with the accompanying drawing which diagrammatically illustrates an Operative arrangement of 'theapparatusk The apparatus, which is mounted within the conditionedspace, consists of an atomizer operating valve I for controlling the on and off periods of a plurality of atomizer heads .(not

shown) which are adapted to atomize water into the space which is to be humidity controlled or conditioned. The atomizer roperating valve is controlled by air pressure acting on a bellows diaphragm-2 or other pressure-responsive means,

movement of said diaphragm functioning to seat and unseat an air valve 3 in ahousing 4 through which the air under pressure is adapted to Vpass to the atomizer heads when the air valve 3 is unseated. Automatic control of thediaphragm 2 in the atomizer operating valve is by air pressure in a pneumatic system comprising a line or conduit 5 leading to said diaphragm and connected with relays 6 and I through conduits 8, 9, i0 and II, the relay I being also connected to a branch line l2 leading from a hygrostat I3 adapted to receive air under ,pressure through the conduit I4, said air pressure being the same as is supplied to the relay 6.

The atomizer operating valve I, herein shown diagramatically, is representative of any type of blow-through diaphragm valve Well known in the art, the pressure on the diaphragm 2 being counteracted by a coil spring I5 and said diaphragm being physically connected with the air valve 3 througha stem orv the like L6. Also carried b y thestem I6 is a second valve member I 'I adapted to engage a bleed-offport I8 in the housing 4', the bleed-oir port being normally closed when the valve 3 is unseated, and vice versa.

The relay 6 is of the reverse actingpositive type nand preferablyhas a narrow range of operation,

for example, one-half pound pressure, and consists of alhousingl 9 having a port 20 therein leading to a valve seat 2l against which is adapted to seat a valve 2 2 carried by one end of a valve stem v23, to the opposite end of which is aixed an enlarged ball 24 adapted to move through and expand an annular coil garter ,spring 25 supported in a saucer frame 26 pivoted at one end 21 toalug 28. 'The saucerfframe 26 carries a pilot pressure-responsive means herein shown as an expansible diaphragm 29havi11g Communication with a port 30 connected with the vduct 8, the housing I9 'having `therein an additional port 3 I connecting with the conduit 5, the inner end of said port leading to thechamber in which the valve 22 is `movable. Also Vextending into said chamber vis a second valve Seat 32 formed on a plug 33 which surrounds the valve stem 23 and against which valve seat 32 the valve 22 `is also adapted to seat when the pilot pressure withinthe expansible diaphragm k291s below the force provided by a tension Spring 3 4 connecting one end The ball Ztl, garter spring 25 and tension spring 34 mavasa Whole be considered to be a diaphragm motor for controllingthe. movements-and seatings loli the ,valve '22. AThe functioning 0f the reverse acting positive relay is as follows: With, say ten pounds gauge pressure and less acting on the diaphragm 29, the working mechanism would be in the position shown on the drawings. When the diaphragm pressure is increased to say ten and one-half pounds, the saucer frame 26 moves clockwise about its pivot point 2'I, causingr the ball 24 to expand the annular coil spring 25, and when the median plane ofthe ball 24 passes the median plane of the spring 25, the contracting force of the spring snaps the ball to the left, causing the valve 22 to move against the seat 2 I With the valve 22 in this position the inner end of port '3l is open to atmosphere through the annular space around the valve stem 23. In other words, the air pressure in the conduit and acting upon the diaphragm 2 of the atomizer operating valve I is bled out to the atmosphere whereupon the valve member 3 will be unseated by the force of spring I5, the valve member I'I will be seated, and air under atomizing pressure from a supply source will pass through the valve housing 4 to operate the atomizer heads. At the same time constant air line pressure of say fteen pounds (gauge indication) from the supply line 35 will likewise be closed off at the valve seat 2I. However, when the air pressure in diaphragm 29 is lowered to ten pounds the spring 34 will cause the saucer member 26 to move in a counterclockwise direction and the valve 22 will be snapped back to the position shown in the drawing.

The relay 'I is of the direct acting positive type and has a range of from ten to fourteen pounds. The construction of this relay is somewhat similar to that of relay 6 and the parts of relay 'I corresponding to those of relay 6 will be designated by the same reference numerals, to which the letter a has been added. In the drawing, this relay 'I is shown in its normal position with no air pressure other than atmospheric pressure acting on diaphragm 29a which is connected through port 30a with the line or conduit II. In this position the valve member 22a is closed against the seat 2| a shutting off conduit I2 and opening conduit 8 to the atmosphere around the valve stem 23a. L

When the pressure in diaphragm 29a, increases suiciently to overcome the tension in the adjustable frame spring 34a the saucer frame 26a moves in a counter-clockwise direction around its pivot point 21a expanding the annular coil spring 25a over the central plane of the ball 24a. When the snap spring 25a has passed over the central plane of the ball 24a its contracting force snaps said ball to the right causing the valve 22a to close against the seat 32a, thereby closing conduit 8 to the atmosphere and connecting said conduit with conduit I2.

Branch conduits 9 and I0 connecting conduits 5 and II are each provided with a check valve 36 and 33a respectively opening in the direction indicated by the arrows and with a restricter valve 3'! and 31a respectively for controlling the 01T time interval and the on time interval of the atomizer operating valve I.

The hygrostat I3 is of the reverse acting type, i. e., it will increase the air pressure in the branch line or conduit I2 on a decrease in humidity in contact with the hygroscopic element (not shown) of the hygrostat. On a rise in humidity, the pressure in the branch line I2 will be bled out through a vent (not shown). The type of hygrostat used is well known and one embodiment thereof is illustrated and described in detail in drawing 6547 in a pamphlet entitled Instructions for Taylor Room Type Hygrostat and Relay,

'4 Copyright 1936, by Taylor Instrument Company, Rochester, New York.

Sequence of timer operation With an excess of humidity in the atmosphere surrounding the hygrostat I3, the gauge air pressure in hygrostat branch conduit I2 will be below ten pounds which is the snap point of the reverse acting relay 6. Now by way of example let us say that branch line I2 is at zero gauge pressure, or atmospheric pressure. When such is the case, the pressure in conduit 8 must also be at zero pressure as the conduit 8 is either connected to the conduit I2 or is open to atmosphere. Diaphragm 29 is therefore also at zero pressure.

VAs described hereinbefore, with zero pressure on diaphragm 29 the fifteen pounds air line pressure connected to port 20 is open to conduit 5. With iifteen pounds pressure on conduit 5 there is fteen pounds pressure on the diaphragm 2 of the atomizer control valve I which operates to move the valve member 3 down upon its seat, cutting off the supply of air to the atomizer heads. The downward movement of the valve stem I6 which carries the valve member 3 also moves the valve disc I1 off its seat and the air pressure still on the atomizer heads side of the valve housing 4 is bled oli" through the now open but vnormally closed bleed-oir port I8. With fifteen pounds pressure still in the conduit 5 the pressure in the conduits 9 and I I will gradually build up through the downwardly opening check valve 3B and restricter valve 3'I. When the pressure in the conduit I I and acting upon the expansible diaphragm 29a reaches fourteen pounds, said pressure acting on diaphragm 29a causes the valve 22a to seat against the exhaust port seat 32a. and connects conduits I2 and 8 through ports 30a and 3Ia. If desired, the conduits 9 and II may also connect through a branch or extension II a with a volume chamber 39.

The conditions described in the preceding paragraph with respect to pressures and valve positions occur with a humidity condition at the hygrostat I3 in excess of the lower of the prel scribed limits.

On a drop in humidity in the atmosphere sur rounding the hygrostat to below the lower of the prescribed limits for the conditioned space, the air pressure to the conduit I2 will be increased by the hygrostat. This pressure will increase gradually and will be communicated from conduit I2 through valve seat 2Ia., port 3Ia and conduit 8 into diaphragm 29Yin relay 6. When the pressure in diaphragm 29 reaches ten and one-half pounds the valve member 22 will move to the left against the valve seat 2 I, closing 0E the constant fteen pounds air supply and exhausting the air pressure in conduit 5 through the annular space around the valve stem 23. As the air pressure drops in conduit 5 the tension provided by spring I5 upon the atomizer diaphragm 2 will snap the valve discs I'I and 3 to their normal positions, with the member I 'I seated and the member 3 unseated. This permits air at thirty-iive pounds pressure to again feed through the valve housing 4 to the atomizer heads and start them operating. Upon atmospheric pressure being reached in the conduit 5, the air pressure in the volume chamber 39, conduit II and expansible diaphragm 29a. will dropl slowly as the air leaks back through conduit I0, restricter valve 31a and check valve,36a into conduit 5 and out to atmosphere through the annular space around the valve stem 23. When 'berl'S-S may be omitted` yConduit l! and expansiblediaphragm 29a builds @comme the pressure Vin diaphragm '29a `drops to ten Ppounds, valve 22a lwill'be snapped onto its seat -2iaopeningport Bld to atmosphere .to bleed the Lairffronidiaphragm29. When the air pressurel lnconduitilfand expansible diaphragm'ZS drops,

erating valve Vdiaphragm and seats the valve 'Bland unseats'the valve I1, thus cutting oif the -operationlof the atomizerheads. The air-incon- 'duit 5 'at'fifteen'pounds gage lpressure starts to i-build up slowly in conduits "-9, H, vv-'olumercham-l :berand expansible diaphragm 23d. The rate of Iairliow from conduit 5 toiconduit -past the re 'stricter valve 3i depends on the setting oi the restricter valve 3l and the size of the volume ,chamber 33.

Under certain conditions and ad- `ljustment of restricter valve 3l the volumechamlWhen the pressure in Yup to fourteen pounds -the valve disc 22a will again move tothe right, closing oif'thebleed-of A:port through valveseat 32u, and again connecting conduits IfZ-andf. If the pressure in con- ,.duitsi'2, 8 and diaphragm ida is still above ten 'andorre-half pounds, the valve disc'22 will move 'toi-the left and the air in `conduit 5 under fteen :pounds-gage pressure will again exhaust to the' .atmosphere through the space `around the valve rstem'i.'

The-interval of time during which-the -atomizer -headscan stay on depends on the setting of the '.'restricter valve Bla, while the interval of time during which they can remain off when `the hygrostat is calling for humidication is controlled by the setting of the restricter valve 31.

The operating constant air pressure supplied v.to the atomizer control ,.valvefandtothe hygrostat may be arbitrarily chosen, ,however said pressure must -be somewhat rgreater than the pressures at which the pressure-responsive members o'f'the relays are adapted to operate. Also,

'fthe operating pressure vranges v`of the :pressurevresponsive members of the relays maybe varied provided one of said pressure-responsive Ymembers operates Within a-narrow range.

Accordinglywhile'l haveshown and described -a-singleembodiment of my invention, 'I vdonot intend that vsuch vdisclosure be considered 'as space produced by such addition of water, and g automatically interrupting said intermittent atomizing of water into said space by a hygrostat pneumatic control in said space when the relative humidity in said space is at the higher of the prescribed limits and again restoring the intermittent atomizing of water into said space when said relative humidity drops to the lower of the prescribed limits.

is '32. Ain -apparatusfor controlling vandv maintaining the relativehumidity of fair .within agiven space within prescribed limits, `,comprising a pneumatically Ycontrollable system including therein an atomizer control valve, pneumatic pressureresponsive means ffor Vopening and closv-ingsaid valve,and1a hygrostat, said pneumatic 'pressure-responsive `means being operative to Vautomaticallyopen and close the atomizer 'con- 'vtrol valveat denitely 'timedinterv-als to .alter- 'rnately-atomize waterinto the given space "and to v'cut 'off fsuch atomization, and said Ahygrostat being operative Ltocontrol -the flow of vair inthe vpneumatically `controlled system to interrupt rv'said `intermittent 'openinglof the atomizer con-- ltrol valve whenthe-relative humidity in the given 'space is at the higherV of the prescribedrhumdity limits.

T3. `An apparatus :for controlling and maintainingthe relative humidity of 'air within a given spa'ce within prescribed limits, comprising a pneumatically controllable system including 4'therein van vatomizer control valve, two relays Ieachhaving avalveand a pneumatic pressure Vresponsivefmeans .for opening and closing Ysaid. valve, land a hygrostat, said relays-being connected. yin series and voperative `to automatically -openand close thezatomizer control'valve at defl- .nitely timed intervals to alternately atomize `water -into the given space'an'd -to cut off such' 'atomizatiom and said hygrostatl-beingoperative `to *control Athe :flow of fair 'inthe `pneumatically controlled system to interrupt-said intermittent opening of the atomizer control valve when'the vrelative humidity in fthe given space -is Aat the vhigher of fthe prescribed humidity limits.

vIl. An apparatus according to claim 3 wherein vthe pneumatically controlled system vincludes Ytwo branch 'conduits connecting the pneumatic .pressure supply'line toithe-atomizer control valve With-the pressure-responsivevelementof one oi' lthe relays, l'each branchconduit having a check valve-and arestricter valve therein, and the check -valve Ain the respective branch v conduits opening toair'pressure iiowin 'opposite directions.

"5. Ani-*apparatusaccording'to claim 3 wherein 'onefof the relays 'has a valved port connecting `witlfr-a *source .of vconstant -air kpressure and :adapted lto supply such air pressure to the -atomiz er control valve, andv the pressure-respon- .'.sive f-means of 'said relay is connected through Vthe'valve ofthe second relay toa conduit through `Whichthe passage of 'air 'is controlled by the h-ygrostat, .the pressure-responsive member of the rst relay being operative through a pressure range of less than one pound to open and close the valve of said relay and the pressureresponsive member of the second relay being operative through a pressure range of several pounds to open and close the valve of the second relay.

6. An apparatus according to claim 3 wherein one of the relays has a valve port connecting with a source of constant air pressure and adapted to supply such air pressure to the atomizer control valve, and the pressure-responsive means of said relay is connected through the valve of the second relay to a conduit through which the passage of air is controlled by the hygrostat, the pressure-responsive member of the second relay being adapted to receive pressure through a branch conduit from the constant air pressure being supplied to the atomizer control valve, said branch conduit having therein a check valve and a restricter valve, said check valve being adapted I to open under the constant air pressure and said restricter valve being adapted to control the o time operation of the atomizer control valve.

7. For use in apparatus for controlling and maintaining the relative humidity of air within a given space, comprising a pneumatically controlled system including an atomizerY control valve and a hygrostat adapted to control the ow of air in the pneumatically controlled system to open and close the atomizer control valve in response to relative humidity conditions at the hygrostat; a pneumatically controlled unit adapted for connection within said pneumatic system to automatically alternately open and close the atomizer control valve for definite time intervals, said unit comprising a relay adapted for connection in said system between the hygrostat and the atomizer control valve and two branch conduits adapted for connection between the relay and the conduit leading to the atomizer control valve, said relay having a valve and a pneumatic pressure-responsive member for opening and closing said valve, one end of each of the branch conduits being adapted for connection with the conduit leading from the relay to the atomizer control valve and the other ends of the branch conduits being adapted for connection to the pneumatic pressure-responsive member of the relay and each branch conduit having therein a check valve and a restricter valve, with the check valves in the respective branch conduits opening to air pressure flow in opposite directions.

8. For use in apparatus for controlling and maintaining the relative humidity of air within a given space, comprising a pneumatically controlled system including an atomizer control valve and a hygrostat adapted to control the flow of air in the pneumatically controlled system to open and close the atomizer control valvein response to relative humidity conditions at the hygrostat; a pneumatically controlled unit adapted for connection within said pneumatic system to automatically alternately open and close the atomizer control valve for definite time intervals, said unit comprising two relays in series adapted for connection in said system between the hygrostat and the atomizer control valve, each of said relays having a valve and a pneumatic pressure-responsive member for opening and closing said valve, two branch conduits adapted for connection between the conduit leading from the first relay to the atomizer control valve and the second relay, one end of each 8 l of the branch conduits being adapted for connection with the conduit leading from the first relay to the atomizer control valve and the other end of the branch conduits being adapted for connection to the pneumatic pressure-responsive member of the second relay, each branch conduit having therein a check valve and a restricter valve with the check valves in the respective branch conduits opening to air pressure flow in opposite directions.

9. An apparatus for controlling humidication of air within a given space within prescribed limits comprising a pneumatically controlled system including therein an atomizer control valve, a hygrostat, a source of constant air pressure and two pneumatic relays the valves of which are operable by -pilot pressure less than the constant air pressure, said relays being adapted to operate the atomizer control valve to alternately atomiae water into the given space and cut ofi such atomization, one relay being adapted to supply air at constant pressure to the atomizer control valve and receive pilot pressure from the hygrostat through the second relay, the pressure-responsive member of said second relay being connected through two branch conduits with the constant air pressure being supplied to the atomizer control valve, a check valve and a restricter valve in each of said branch conduits, the checl; valve in one branch conduit opening to the constant pressure and the restricter valve in said conduit controlling the oir time of the atomizer control valve, the check valve in the other branch conduit closing to the constant pressure and opening to pilot pressure from said second relay and the restricter valve in said second branch controlling the on time of the atomizer control valve.

OWEN T. MERVIIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,270,159 Hodge June 18, 1918 1,513,727 Kriek Oct. 28, 1924 1,597,349 Fortier Aug. 24, 1926 1,758,494 Behr May 13, 1930 1,860,377 Anderson May 31, 1932 2,285,540 Stein June 9, 1942 2,387,562 Brunot Oct. 23, 1945 

